1. Field of the Invention
The present invention relates to a controlling method for a hard disk drive (HDD) and a data processor provided with the HDD, in particular to a controlling method for the HDD and a data processor reducing power consumption of the HDD.
2. Description of the Related Art
Various kinds of power-saving measures are implemented in order to suppress wasteful power consumption when the battery is operated in the portable type information processing appliances which are capable of being driven by a battery-drive.
Also, various kinds of power-saving measures are implemented in the information processing measures such as the personal computer in which the hard disc drive (HDD) is loaded.
Conventionally, as the power-saving measure, there exists a method for saving power by stopping a motor for driving HDD, when HDD is not accessed during predetermined period of times.
However, in the power saving method, when the motor of HDD once stops, in order to restart the motor, it requires latency of 3 to 5 seconds extends, accordingly there is a problem that it is not easy to use therefor.
In order to start the HDD motor, when the motor starts, exceedingly large starting current becomes necessary. The starting current is exceedingly larger than the normal driving current when the motor rotates with constant motor speed. There is accordingly a problem that the large starting current becomes adverse effect for the power saving. Further there is a problem that the life of the HDD becomes short life, if the motor of the HDD stops at frequent intervals for power saving thereof.
From these problems, it is incapable of being expected so large in a power saving to shorten the period of established time for controlling a period of time of motor-off, in case of shifting to the motor-off after accessing of the HDD.
There is a power saving measure as the conventional power saving measure of the HDD that the motor is transferred from the driving condition to the idle condition when the motor stands off-condition.
There is a problem that the power saving measure for power consumption of the HDD by motor-off becomes adverse effect when the motor-off is repeated frequently as stated above. In the saving measure of the power consumption in which the saving measure comes into the automatic idle after disk accessing, since the off controlling of the motor is not implemented, a large power saving effect can not be expected.
Conventionally, there is an operational function for reducing the power consumption in that the motor is automatically transferred from the driving condition to the idle condition, at the time when 5 seconds elapse from termination of read/write of HDD. However, with regard to this operational function, the automatic idle timer which controls the automatic idle period of time of the HDD is fixed to 5 seconds, accordingly, there is a problem that wasteful power consumption is consumed during 5 seconds period of time when the motor comes into the idle condition from the HDD accessing.
Further conventionally, in the personal computer which is capable of being driven by the battery, respective display and HDD, in which the procession for the power saving is implemented individually. Namely, with regard to the display, the input operating condition of the key board/mouse is supervised by the exclusive timer, and if there is no input, the operational function of display-off is provided by an operating system. With regard to HDD, the power saving operational function such as motor-off and so forth are implemented due to the access-supervision of the HDD by using the individual exclusive timer.
At this period of time, when the timer of the HDD is established for a longer period of time rather than the timer of the display, if the user does not employ the personal computer more than established period of the time, although the power saving operational function of the display operates, the power saving operational function of the HDD does not operates, consequently, improvement of the power saving effect is not attained.
Furthermore, in the conventional power saving method, the HDD is supervised by the timer, and if the HDD is not accessed within the predetermined period of the time, the power saving is performed by stopping the motor of the HDD. At this time, the automatic stop period of time established to the timer is always fixed period of the time. When the personal computer is employed by the battery, if the automatic stop period of time is shortened, power consumption of the battery is reduced, however the extent of easy-to-use is deteriorated. While if the automatic stop period of time is lengthened, the extent of easy-to-use is improvement, the power consumption of the battery is increased.
Thus, conventionally, since the automatic stop-period of time of the HDD is fixed, there are problems that the attempt of the power saving might result in poor extent of easy-to-use for the user, while when the extent of easy-to-use for the user is taken into consideration, high effective power saving is incapable of being expected.
As described above, in the conventional data processing apparatus, since the automatic stop-period of time of the HDD is fixed, there are problems that the attempt of the power saving might result in poor extent of easy-to-use for the user, while when the extent of easy-to-use for the user is taken into consideration, high effective power saving is incapable of being expected.